Year | Value | 2021 | 48 | 2020 | 673.09 | 2019 | 2,623 | 2018 | 3,205 | 2017 | 3,577 | 2016 | 3,102 | 2015 | 3,012 | 2014 | 2,214 | 2013 | 2,556 | 2012 | 8,091 | 2011 | 9,148 | 2010 | 8,875 | 1998 | 6,500 | 1997 | 6,400 | 1996 | 5,100 | 1995 | 5,100 | 1994 | 4,600 | 1993 | 4,600 | 1992 | 4,500 | 1991 | 3,400 | 1990 | 3,400 | 1989 | 2,300 | 1988 | 2,100 | 1987 | 2,100 | 1986 | 1,800 | 1985 | 2,200 | 1984 | 2,000 | 1983 | 2,000 | 1982 | 3,100 | 1981 | 3,100 | 1980 | 3,200 | 1979 | 4,300 | 1978 | 4,400 | 1977 | 5,000 | 1976 | 4,500 | 1975 | 3,700 | 1974 | 3,200 | 1973 | 1,800 | 1972 | 8,300 | 1971 | 8,200 | 1970 | 10,500 |
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